NMES to Improve Hip Abductor Strength and Balance

Falls are a leading cause of disability in older adults. Decreased lower extremity muscle
mass and strength contribute to balance and mobility limitations. Our more recent work also
suggests that in addition to the traditional targets of muscle mass of the thigh and leg
muscles, dysfunction of the hip abductors may contribute to balance and mobility limitations
resulting in increased fall risk. Older adults with impaired hip abductor muscles demonstrate
increased amounts of intramuscular fat (IMAT) in and around the muscles, decreased hip
abductor strength, lower balance scores, increased gait variability (a predictor of future
falls), and poor stepping mechanics when recovering from a balance perturbation. Increased
IMAT and muscle dysfunction of the hip abductors may contribute to poor hip abductor muscle
recruitment and make changing these muscle during a traditional intervention difficult.
Neuromuscular electrical stimulation (NMES) is one method to improve muscle mass, strength
and quality in older adults, but has not traditionally been used on the hip abductors. We
propose that a targeted multimodality balance intervention (MMBI) focused on the lateral and
diagonal stepping and hip abductor strengthening when combined with NMES will result in
improvements in mobility and balance.

Inclusion Criteria:

Mobility and balance limitations as demonstrated by a self-reported fall within the past
year or requiring greater than 8 seconds to complete the 4-square step test

Exclusion Criteria:

1. Cardiovascular Risks: Poorly controlled hypertension (>160/100); or patient report of:
symptomatic angina at rest or during exercise, syncope without known resolution of
cause, or a significant coronary event (such as a MI) in the past six months

2. COPD requiring home oxygen

3. Contraindications to resistance training, including a self-reported history of
intracranial or retinal bleeding in the last year or Diabetes with active
proliferative retinopathy

4. Patient report of significant spinal stenosis that would limit participation in the
exercise intervention

5. Non-ambulatory mobility status or a transtibial or transfemoral amputation

6. Dementia (on medical record review or mini-mental status exam score <24).

7. Other severe medical illness or condition that would preclude safe participation in
the study as determined by the study team